Vertically-stacked interdigitated metal-insulator-metal capacitor for sub-20 nm pitch
View Patent ↗An interdigitated metal-insulator-metal capacitor structure is formed by a first unitary body of a first conductive material that includes a first metal plate, a first set of interdigitated electrodes protruding upwards from a top surface of the first metal plate, and a first set of connecting vias protruding downwards from a bottom surface of the first metal plate. A second unitary body of a second conductive material is disposed above the first unitary body and electrically separated from the first unitary body by an insulating layer. The second unitary body includes a second metal plate, a second set of interdigitated electrodes protruding downwards from a bottom surface of the second metal plate, and a second set of connecting vias protruding upwards from a top surface of the second metal plate. The first set of interdigitated electrodes are interleaved with the second set of interdigitated electrodes.
1. An interdigitated metal-insulator-metal capacitor structure, comprising:
a first unitary body of a first conductive material comprising a first metal plate, a first set of interdigitated electrodes protruding upwards from a top surface of the first metal plate, and a first set of connecting vias protruding downwards from a bottom surface of the first metal plate;
a second unitary body of a second conductive material disposed above the first unitary body, the second unitary body comprising a second metal plate, a second set of interdigitated electrodes protruding downwards from a bottom surface of the second metal plate, and a second set of connecting vias protruding upwards from a top surface of the second metal plate, the first set of interdigitated electrodes being interleaved with the second set of interdigitated electrodes, each of the first set of interdigitated electrodes and the second set of interdigitated electrodes having an aspect ratio of at least 1:1; and
an insulating layer disposed between the first unitary body and the second unitary body for electrically separating the first set of interdigitated electrodes from the second set of interdigitated electrodes to form the interdigitated metal-insulator-metal capacitor.
2. The interdigitated metal-insulator-metal capacitor structure of claim 1 , wherein the first conductive material comprises at least one of cobalt, ruthenium, aluminum, titanium, and tungsten.
3. The interdigitated metal-insulator-metal capacitor structure of claim 1 , wherein the second conductive material comprises at least one of cobalt and ruthenium, aluminum, titanium, and tungsten.
4. The interdigitated metal-insulator-metal capacitor structure of claim 1 , wherein the insulating layer comprises a high-k dielectric material.
5. The interdigitated metal-insulator-metal capacitor structure of claim 4 , wherein the high-k dielectric material comprises at least one of aluminum oxide, hafnium oxide, and tantalum oxide.
6. The interdigitated metal-insulator-metal capacitor structure of claim 1 , wherein the first set of interdigitated electrodes and the second set of interdigitated electrodes having the aspect ratio of at least 1:1 increases a total capacitance of the metal-insulator-metal capacitor structure.
7. The interdigitated metal-insulator-metal capacitor structure of claim 1 , further comprising:
a second insulating layer disposed above a semiconductor substrate and below the first set of connecting vias.
8. The interdigitated metal-insulator-metal capacitor structure of claim 7 , wherein the second insulating layer comprises nitrogen-doped silicon carbide.